fix(stake): deposit-cap principal basis (#154) + clear deposit record on full withdraw (#155)

[dcccrypto]

Fixes #154 (deposit cap counted accrued fees → spurious lockout) and #155 (deposit-PDA tranche flag persisted after full withdrawal → wallet permanently blocked from the other tranche). See commit for the mechanism + safety analysis. #157 deliberately NOT fixed — on my own analysis it is not a reachable bug (a fee-enriched junior always covers any loss ≤ deposited, so the gross_senior saturation never affects the result); I reverted the speculative change and will note it on #157. Build-sbf clean; suite green except the 4 pre-existing v17_stake_insurance_e2e LiteSVM failures.

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Fixed deposit cap enforcement in mode-1 trading pools to exclude accrued fees, preventing legitimate deposits from being incorrectly rejected.
  • Deposit records can now be reused for either tranche on subsequent deposits.

• Tests

  • Added regression test to validate deposit cap enforcement behavior with accrued fees.

[coderabbitai]

Caution

Review failed

The pull request is closed.

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: aaefc837-95aa-4520-890c-0fcdc0be3f57

📥 Commits

Reviewing files that changed from the base of the PR and between 3b5679d and f027b15.

📒 Files selected for processing (3)

• src/processor.rs
• src/state.rs
• tests/unit.rs

---

📝 Walkthrough

Walkthrough

Adds StakePool::principal_tvl() that computes TVL excluding accrued trading fees, then replaces total_pool_value() with principal_tvl() in both deposit-cap checks. On full withdrawal (lp_amount == 0), the deposit PDA's is_initialized and tranche flag are cleared to allow reuse. A regression test validates all three behaviors.

Changes

Principal TVL deposit-cap enforcement and deposit PDA reuse

Layer / File(s)	Summary
StakePool::principal_tvl() method src/state.rs	New method computes total_deposited - total_withdrawn - total_flushed + total_returned via checked arithmetic, explicitly omitting total_fees_earned that total_pool_value() adds in mode-1 pools.
Deposit cap checks switched to principal_tvl() src/processor.rs	Both process_deposit (line 496–498) and process_deposit_junior (line 2201–2203) now call principal_tvl() instead of total_pool_value() when evaluating the deposit cap, so fee appreciation in mode-1 pools no longer contributes to cap consumption.
Deposit PDA reset on full withdrawal src/processor.rs	After burning LP in process_withdraw, if deposit_mut.lp_amount == 0, is_initialized is set to false and _reserved[8] is cleared, permitting the same deposit PDA to be reused for either tranche on a subsequent deposit.
Regression test #154 tests/unit.rs	test_154_deposit_cap_enforced_on_principal_not_fees asserts principal_tvl() excludes fees in mode-1, that a deposit within the principal cap passes despite fee-inclusive value exceeding the cap, and that principal_tvl() == total_pool_value() in mode-0.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• dcccrypto/percolator-stake#98: Modifies the same tranche-mixing anti-bypass logic in process_deposit/process_withdraw that this PR's deposit PDA reset directly relaxes on full withdrawal.
• dcccrypto/percolator-stake#122: Modifies process_deposit_junior's TVL computation in the same function block where this PR switches the deposit-cap basis from total_pool_value() to principal_tvl().

Poem

🐇 Hoppity-hop through the ledger I go,
Fees piled high? They won't block the flow!
Principal only — the cap holds true,
And empty PDAs get a fresh start too.
No silent lockout, no admin surprise —
The burrow stays open under honest skies! 🌿

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/stake-154-155-deposit-cap-and-tranche-flag

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}